We are tasked with solving the integral: \[ \int \frac{dx}{1 + e^x} \] This integral is of a standard form. We recognize that the integral of \( \frac{1}{1 + e^x} \) is directly related to the natural logarithm function.
Specifically: \[ \int \frac{dx}{1 + e^x} = \log|1 + e^x| + C \] where \( C \) is the constant of integration. Thus, the correct answer is \( \log|1 + e^x| + C \).
The integral \(\int e^x \sqrt{e^x} \, dx\) equals:
Kepler's second law (law of areas) of planetary motion leads to law of conservation of